/**
 * #      589
 * 名称   N 叉树的前序遍历
 * 链接   https://leetcode-cn.com/problems/n-ary-tree-preorder-traversal
 * 题解   [437](https://leetcode-cn.com/problems/n-ary-tree-preorder-traversal/solution)
 * 通过率 74.1%
 * 难道   简单
 */

